双抗体夹心生物素-亲和素ELISA法检测相思子毒素

Assay of abrin by double antibody sandwich biotin-streptavidin ELISA

目的建立相思子毒素(abrin)的酶联免疫检测方法,为abrin临床诊断、中毒治疗、法医学鉴定等应用领域提供技术基础和参考依据。方法采用双抗体夹心生物素-亲和素ELISA法来检测微量abrin。结果该法检测abrin线性范围为0.125～31.25μg/L,线性回归方程为Y=0.52369X+0.51632(r=0.9816,P<0.0001,n=9),检测限为0.125μg/L。不同浓度蓖麻毒素(ricin)、葡萄球菌肠毒素(SEB)对检测结果基本无干扰,表明该法检测abrin具有很好的特异性。该法能用于abrin毒素污染水样、土样、食品、血液等模拟样品的分析,相对标准差为2.35%～4.14%,具有较好的重现性。结论成功建立了夹心BA-ELISA法检测abrin,巧妙地将多克隆抗体的强富集能力、单克隆抗体的特异性以及生物素-亲和素系统的放大作用结合起来,达到了提高检测的灵敏度和特异性的目的,可适用于各种微量abrin样品的分析。

Objective To develop an ELISA for abrin determination and provide a technique reference for clinical diagnosis, toxicosis treatment, and medical jurisprudence identification. Methods A double antibody sandwich biotin-streptavidin ELISA （S-BA-ELISA） procedure was used for abrin assay. Results The detecting linear range for abrin was0. 125 - 31.25μg/L. The linear regression equation was Y=0.52369X＋0.51632（r = 0.9816, P〈0.0001, n =9）with the detection limit of 0.125 μg/L. Riein and staphylococcal entemtoxin B （SEB） in different concentrations did not interfere the abrin assay by S-BA-ELISA, which demonstrated that the method had a good specificity. This approach showed good reproducibility with relative standard deviation ranged from 2.35% to 4.14%, which could be used for analyzing abrin-contaminated specimens such as water, soil, food, and blood, etc. Conclusion S-BA-ELISA was successfully developed to detect abrin. This method combined the high affinity of polyclonal antibodies （PcAb）, good specificity of monoclonal antibodies （McAb）, and the amplification effect of BAS （Biotin-avidin system）, which greatly improved the sensitivity and specificity and could be suitable for trace abrin assay.